Very possible. Clearly he's a lot older now than when Draxum nabbed him, so if he was a fighter in the Battle Nexus then it may have been in his younger days as Splinter, before the Turtles came along.

Which also could mean that he may have lived in that city for a while before the turtles were "born" and subsequently taken away from that place? If so, I'm curious how long he was possibly living there.

And if by chance the Turtles were created because Draxum wanted newer, tougher models, since Splinter was aging, and Spinter didn't want them stuck in a life of being kept like captives and used as fighters for someone else's sport, or used for worse.

Anyway... Splinter is so short though, what the heck would a trim, built version even look like since he didn't keep his human height? lol

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"Breath in the smoke, Oroku Saki, and meditate. Open your mind and all will become clear."-Kitsune, SHotFC #3

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